Category Archives: Chronic Pain

Cannabidiol engages the peripheral endogenous opioid system to produce analgesia in neuropathic mice

Posted on by
pubmed logo

“Cannabidiol (CBD) has been getting attention from the scientific community regarding its potential for the treatment of different conditions, such as epilepsy, anxiety, and pain.

This potential can be useful in clinical practice as an alternative or as an adjuvant alongside conventional therapeutic approaches; however, its mechanisms of action should be best described for its more effective application. Thus, our study aimed to evaluate whether the peripheral opioid system is involved in the analgesic mechanism of cannabidiol administered systemically for the treatment of neuropathic pain.

Male Swiss mice were subjected to the sciatic constriction injury, and their nociceptive threshold was evaluated using the mechanical paw pressure test.

Cannabidiol 20 mg/Kg produced an antinociceptive effect. Bestatin (400 µg/paw), a selective aminopeptidase-N inhibitor, potentiates the intermediate analgesic response of CBD at the dose of 2 mg/Kg. Naloxone (50 µg/paw), a non-selective opioid receptor antagonist, reversed the CBD-mediated analgesia. CTOP (5, 10, and 20 µg/paw) and naltrindole (30, 60, and 120 µg/paw), μ and Δ opioid receptor antagonists, but not norBNI (200 µg/paw), a κ opioid receptor antagonist, partially reversed the CBD analgesia.

Thus, our study shows that cannabidiol may induce activation of opioid receptors in the periphery as a part of its analgesic mechanism in neuropathic pain.”

https://pubmed.ncbi.nlm.nih.gov/41022278/

“CDB induces the activation of µ and δ opioid receptors as a part of its analgesia mechanism, leading us to suggest a possible interaction between opioid and cannabinoid systems as a complementary mechanism for generating peripheral analgesia in neuropathic mice treated with cannabidiol.”

https://www.sciencedirect.com/science/article/abs/pii/S0304394025002824?via%3Dihub

Full-spectrum extract from Cannabis sativa DKJ127 for chronic low back pain: a phase 3 randomized placebo-controlled trial

Posted on by

“Chronic low back pain (CLBP) affects over half a billion people worldwide. Current pharmacologic treatments offer limited efficacy and carry substantial risks, warranting the development of safe and effective alternatives.

This multicenter, randomized, placebo-controlled phase 3 trial evaluated the efficacy and safety of VER-01 in CLBP. It enrolled 820 adults with CLBP (VER-01, n = 394; placebo, n = 426) and included a double-blind 12-week treatment phase (phase A), a 6-month open-label extension (phase B), followed by either a 6-month continuation (phase C) or randomized withdrawal (phase D). The primary endpoint of phase A was a change in mean numeric rating scale (NRS) pain intensity, with a change in total neuropathic pain symptom inventory (NPSI) score as a key secondary endpoint in participants with a neuropathic pain component (PainDETECT > 18). The primary endpoint for phase D was time to treatment failure.

The study met its primary endpoint in phase A, with a mean pain reduction of -1.9 NRS points in the VER-01 group (mean difference (MD) versus placebo = -0.6, 95% confidence interval (CI) = -0.9 to -0.3; P < 0.001). Pain further decreased to -2.9 NRS points in phase B, with effects sustained through phase C.

The study also met its key secondary endpoint of phase A, with a mean NPSI decrease of -14.4 (standard error, 3.3) points from baseline in the VER-01 arm (MD versus placebo = -7.3, 95% CI = -13.2 to -1.3; P = 0.017). Although phase D did not meet its primary endpoint (hazard ratio = 0.75, 95% CI = 0.44-1.27; P = 0.288), pain increased significantly more with placebo upon withdrawal (MD = 0.5, 95% CI = 0.0-1.0; P = 0.034). In phase A, the incidence of adverse events-mostly mild to moderate and transient-was higher with VER-01 than with placebo (83.3% versus 67.3%; P < 0.001). VER-01 was well-tolerated, with no signs of dependence or withdrawal.

VER-01 shows potential as a new, safe and effective treatment for CLBP.”

https://pubmed.ncbi.nlm.nih.gov/41023483/

“In conclusion, this phase 3 study provides robust evidence supporting the efficacy and safety of VER-01 in the treatment of CLBP.”

https://www.nature.com/articles/s41591-025-03977-0

“Cannabis extract found to be effective for lower back pain” https://www.newscientist.com/article/2498064-cannabis-extract-found-to-be-effective-for-lower-back-pain/

Cannabis sativa Root Extract Exerts Anti-Nociceptive and Anti-Inflammatory Effects via Endocannabinoid Pathway Modulation In Vivo and In Vitro

Posted on by

“Cannabis sativa root has traditionally been used to relieve pain and inflammation, but its pharmacological properties remain underexplored due to low levels of psychoactive cannabinoids.

This study aimed to investigate the anti-inflammatory and antinociceptive effects of the ethyl acetate fraction of Cannabis sativa root (CSREA) using in vivo rodent pain models. Mice were subjected to formalin and acetic acid-induced nociceptive tests, while rats were evaluated using a carrageenan-induced paw edema model.

CSREA significantly reduced pain-related behaviors in both early (0-10 min) and late phases (15-30 min) of the formalin test and decreased writhing responses in the acetic acid model. Notably, CSREA also improved survival rates following acetic acid injection. Inflammatory markers, including IL-6 and IL-1β, were significantly lowered in serum.

Furthermore, CSREA suppressed paw edema and redness in the carrageenan-induced rat model, demonstrating dose-dependent anti-inflammatory efficacy comparable to diclofenac. CSREA also downregulated pain-related gene expression (SCN9A, ASIC1A, TACR1) and regulated key enzymes involved in endocannabinoid metabolism (FAAH, MAGL, DAGL), suggesting its role in the molecular modulation of pain pathways.

These effects are likely mediated via modulation of the endocannabinoid system, particularly by rebalancing the CB1R/CB2R ratio. The findings suggest that CSREA holds promise as a natural therapeutic agent for managing pain and inflammation and warrants further investigation into its molecular mechanisms and long-term effects.”

https://pubmed.ncbi.nlm.nih.gov/41009431/

“This study provides evidence for the in vivo analgesic and anti-inflammatory effects and underlying mechanism of CSREA in vitro. Our results from the formalin and writhing tests demonstrate that CSREA significantly reduced nociceptive pain-related behaviors and inflammatory cytokine levels indicating strong anti-nociceptive properties in a dose-dependent manner. In addition, CSREA markedly reduced paw edema in the carrageenan-induced rat model, suggesting its potential as a natural product with anti-inflammatory activity. These effects are likely mediated through modulation of the endocannabinoid system, particularly by altering cannabinoid levels as demonstrated in the in vitro model.”

https://www.mdpi.com/1422-0067/26/18/8863

Analgesic and toxicological evaluation of cannabidiol-rich Moroccan Cannabis sativa L. (Khardala variety) extract: Evidence from an in vivo and in silico study

Posted on by

“The legalization of cannabis for industrial and medicinal purposes has significantly expanded worldwide.

This study delves into the analgesic potential toxicity study of chloroformic extract from the Moroccan Cannabis sativa L. (C. sativa) cultivar, Khardala (KH extract). Our findings reveal that the lethal dose of KH extract is ≥5,000 mg/kg, with mice given 2,000 mg/kg exhibiting neurotoxic symptoms, including piloerection, aggressiveness, and fear, along with marked hepato-renal toxicity indicated by elevated levels of alanine aminotransferase, aspartate aminotransferase, total bilirubin, and creatinine in both male and female subjects.

Importantly, no toxicity was observed at 250 mg/kg and 500 mg/kg doses. Remarkably, at a dose of 500 mg/kg, the KH extract demonstrated a potent analgesic effect superior to cannabidiol (CBD), suggesting a synergistic interaction among the extract’s bioactive compounds, such as CBD, cannabidivarin (CBDV), Delta 9 tetrahydrocannabinol (THC), cannabigerol (CBG), Delta 9 tetrahydrocannabivarin (THCV), and β-caryophyllene. 

In silico analysis supports these findings, showing the strong binding potential of THC, THCV, CBG, and CBDV to delta opioid receptors, with G-scores >-5.0 kcal/mol, highlighting the promising analgesic efficacy of this cannabis cultivar extract.

This study underscores the therapeutic potential of the KH cultivar, positioning it as a promising candidate for pain management therapies.”

https://pubmed.ncbi.nlm.nih.gov/40917785/

“In summary, this study contributes to the growing body of research on C. sativa, highlighting the potential therapeutic applications of KH extract in pain management.”

https://www.degruyterbrill.com/document/doi/10.1515/biol-2025-1141/html

UK Medical Cannabis Registry: A Clinical Outcomes Analysis for Complex Regional Pain Syndrome

Posted on by
pubmed logo

“Background: Complex regional pain syndrome is characterized by severe, persistent pain. Emerging evidence suggests that cannabis-based medicinal products may represent a new therapeutic option. However, to date, no clinical studies have evaluated the effects of cannabis-based medicinal products in individuals with complex regional pain syndrome. The aim of this study is to assess changes in patient-reported outcome measures and the prevalence of adverse events associated with cannabis-based medicinal products prescribed for complex regional pain syndrome.

Methods: This case series assessed changes in patient-reported outcome measures over 6 months in complex regional pain syndrome patients enrolled in the UK Medical Cannabis Registry. Adverse events were measured and graded using the Common Terminology Criteria for Adverse Events version 4.0.

Results: A total of 64 patients were identified for inclusion. At baseline, pain severity measured by the Brief Pain Inventory Short Form was 6.69 ± 1.42. This improved at 1 (5.85 ± 1.73), 3 (5.91 ± 1.82), and 6 months (6.05 ± 1.72; p < 0.050). Participants also reported improvements in severity as measured by the Short Form-McGill Pain Questionnaire-2 and pain visual analogue scale at the same time points (p < 0.050). Participants also reported improvements in anxiety symptoms, sleep quality, and general health-related quality of life (p < 0.050), as measured by validated measures. Five patients (7.81%) reported 50 (78.13%) adverse events.

Discussion: This study represents the outcomes in individuals with complex regional pain syndrome prescribed cannabis-based medicinal products. These suggest initiation of cannabis-based medicinal products is associated with improvements in patient-reported outcome measures. While these findings are consistent with the literature, they must be interpreted with caution, considering the limitations of this study.

Conclusion: Cannabis-based medicinal products were associated with improvements in pain severity and interference. Participants also reported improvements in important metrics of health-related quality of life. This supports further research through high-quality randomized controlled trials to ascertain the efficacy of cannabis-based medicinal products in improving complex regional pain syndrome symptoms.”

https://pubmed.ncbi.nlm.nih.gov/40898690/

“In conclusion, the results imply that initiation of CBMPs was associated with improved pain relief and health-related quality of life in complex regional pain syndrome patients.”

https://onlinelibrary.wiley.com/doi/10.1002/brb3.70823

Delta-9-tetrahydrocannabinol and Cannabidiol for Pain: Preclinical and Clinical Models

Posted on by
pubmed logo

“Cannabinoids are increasingly being used to manage pain resulting from a variety of conditions.

Both preclinical animal models and human studies have played a crucial role in advancing our knowledge of cannabinoids, their involvement in pain mechanisms, and their potential utility as novel analgesics.

This chapter first reviews basic pain neurobiology and the most common experimental pain paradigms, which provide a basis for our discussion of preclinical, human laboratory, and clinical research characterizing the effectiveness of cannabinoids for managing pain.

While a substantial body of literature exists describing these effects, findings are complex and largely mixed, dependent on the cannabinoid administered, route of administration, and pain modality/syndrome tested. Herein, we highlight the need for more rigorous, placebo-controlled research defining the therapeutic efficacy of cannabinoids.

The chapter concludes by emphasizing the need for further investigation of other cannabis constituents (e.g., minor cannabinoids and terpenes), potential interactions between cannabinoids and other analgesic medications, as well as other emerging issues in the intersection between cannabinoids and pain management.”

https://pubmed.ncbi.nlm.nih.gov/40877567/

https://link.springer.com/chapter/10.1007/7854_2025_604

Opioid reduction in patients with chronic non-cancer pain undergoing treatment with medicinal cannabis

Posted on by
pubmed logo

“Introduction: Opioid sparing by co-prescription of cannabinoids may enable patients to reduce their opioid consumption prescribed for chronic benign pain.

Methods: One cohort attending a small private pain clinic (N = 102), already taking opioids, was co-prescribed cannabinoids and another cohort (N = 53) attending a separate pain clinic nearby received only opioids. The two groups were studied prospectively for a year before their drug consumption was assessed.

Results: At baseline, median opioid consumption was 40 mg/day in both cohorts. Medicinal cannabis was administered daily in an oil formulation usually starting at 2.5 mg/day and was titrated to maximize benefits. At 12 months, the median dose contained 15 mg delta-9-tetrahydrocannabinol and 15 mg cannabidiol. At one-year follow-up, 46 of 102 cases had dropped out compared with only one of 53 controls. Opioid consumption had decreased significantly at one-year follow-up, the final median dose being lower in cases (2.7 mg/day) than controls (42.3 mg/day) (p < 0.05 in an intention-to-treat analysis). Disability and insomnia had also decreased in cases.

Conclusion: The introduction of cannabinoids can produce useful reductions in opioid consumption in real-world settings, with additional benefits for disability and insomnia. However, this treatment is tolerated by only a subgroup of patients.”

https://pubmed.ncbi.nlm.nih.gov/40788193/

“Plain language summary

Morphine-like drugs (opioids) decrease pain but can cause severe breathing problems and death if these drugs are consumed in excessive amounts. Stopping these drugs suddenly (going “cold turkey”) can cause severe adverse effects and, as time goes on, increasing amounts may be required to reduce pain. It might be possible to reduce opioid consumption by also taking medicinal cannabis; otherwise, reduction can be difficult to achieve. Cannabis treatment is safe when the hallucinatory component of cannabis is kept to low levels, causing minimal euphoric effects (a “stoned” sensation).In this study, two groups of patients with chronic pain were studied. Both were taking opioid drugs, but one group also took medicinal cannabis. About half of the medicinal cannabis group were not able to keep taking it due to unpleasant side effects. In the remainder, opioid consumption decreased significantly after both 6 and 12 months. Physical activity and sleep also improved. These findings indicate that medicinal cannabis can help patients to reduce their opioid consumption and improve their physical activity and sleep.”

“These findings indicate that medicinal cannabis can help patients to reduce their opioid consumption and improve their physical activity and sleep.”

https://www.tandfonline.com/doi/full/10.1080/17581869.2025.2544511

Medical Cannabis Use and Healthcare Utilization Among Patients with Chronic Pain: A Causal Inference Analysis Using TMLE

Posted on by

“Introduction: Chronic pain affects approximately 20% of U.S. adults, imposing significant burdens on individuals and healthcare systems. Medical cannabis has emerged as a potential therapy, yet its impact on healthcare utilization remains unclear.

Methods: This retrospective cohort study analyzed administrative data from a telehealth platform providing medical cannabis certifications across 36 U.S. states. Patients were classified as cannabis-exposed if they had used cannabis in the past year, while unexposed patients had no prior cannabis use. Outcomes included self-reported urgent care visits, emergency department (ED) visits, hospitalizations, and quality of life (QoL), measured using the CDC’s Healthy Days measure. Targeted Maximum Likelihood Estimation with SuperLearner estimated causal effects, adjusting for numerous covariates.

Results: Medical cannabis users exhibited significantly lower healthcare utilization. Specifically, exposure was associated with a 2.0 percentage point reduction in urgent care visits (95% CI: -0.036, -0.004), a 3.2 percentage point reduction in ED visits (95% CI: -0.051, -0.012) and fewer unhealthy days per month (-3.52 days, 95% CI: -4.28, -2.76). Hospitalization rates trended lower but were not statistically significant. Covariate balance and propensity score overlap indicated well-fitting models.

Conclusions: Medical cannabis use was associated with reduced healthcare utilization and improved self-reported QoL among chronic pain patients.”

https://pubmed.ncbi.nlm.nih.gov/40700267/

“The findings of this study suggest, in line with existing research, that medical cannabis is likely an effective treatment option for patients with chronic pain. Moreover, we found that, in addition to an increase in QoL, medical cannabis exposure is associated with lower risk of urgent care and ED visits, when comparing patients who used medical cannabis for at least one year to cannabis-naïve patients. This underscores the potential for not only QoL gains associated with medical cannabis use, but also positive downstream effects on the healthcare system resulting from treatment.”

https://www.mdpi.com/2226-4787/13/4/96

“Cannabis Is An ‘ Effective Treatment ’ For Chronic Pain,
Study Suggests” https://www.forbes.com/sites/ajherrington/2025/07/21/cannabis-is-an-effective-treatment-for-chronic-pain-study-suggests/

Machine-learning of medical cannabis chemical profiles reveals analgesia beyond placebo expectations

Posted on by
pubmed logo

“Background: The efficacy of medical cannabis in alleviating pain has been demonstrated in clinical trials, yet questions remain regarding the extent to which specific chemical compounds contribute to analgesia versus expectation-based (placebo) responses. Effective blinding is notoriously difficult in cannabis trials, complicating the identification of compound-specific effects.

Methods: In a prospective study of 329 chronic pain patients (40% females; aged 48.9 ± 15.5) prescribed medical cannabis, we examined whether the chemical composition of cannabis cultivars could predict treatment outcomes. We used a Random Forest classifier with nested cross-validation to assess the predictive value of demographics, clinical features, and approximately 200 chemical compounds. Model robustness was evaluated using six additional machine learning algorithms.

Results: Here we show that incorporating chemical composition markedly improves the prediction of pain relief (AUC = 0.63 ± 0.10) compared to models using only demographic and clinical features (AUC = 0.52 ± 0.09; p < 0.001). This result is consistent across all models tested. While well-known cannabinoids such as THC and CBD provide limited predictive value, specific terpenoids, particularly α-Bisabolol and eucalyptol, emerge as key predictors of treatment response.

Conclusions: Our findings demonstrate that pain relief can be predicted from cannabis chemical profiles that are unknown to patients, providing evidence for compound-specific therapeutic effects. These results highlight the importance of considering the full range of cannabis compounds when developing more precise and effective cannabis-based therapies for pain management.”

https://pubmed.ncbi.nlm.nih.gov/40670615/

“Chronic pain affects millions of people, and many turn to medical cannabis for relief. However, scientists debate whether cannabis truly reduces pain or if patients feel better simply because they expect it to work (placebo effect). In this study, we looked at 329 people who used medical cannabis and analyzed the chemical makeup of their treatments. Using machine learning, we tested whether the specific chemicals in cannabis could predict who would get pain relief.

We found that patients’ pain improvement could be predicted from the chemical content of their cannabis, even though patients didn’t know what chemicals they were receiving. This suggests that cannabis provides real pain relief beyond just patient expectations.

These findings show that medical cannabis has genuine therapeutic effects for pain management.”

“In conclusion, to the best of our knowledge, our study provides compelling evidence that the efficacy of MC in pain relief is not merely a placebo response but is strongly influenced by its diverse chemical composition. Our findings challenge the traditional focus on THC and CBD as the primary therapeutic agents in cannabis and highlight the importance of considering the full spectrum of chemical compounds present in MC. By embracing a more comprehensive approach to understanding MC’s therapeutic potential, we can work towards developing safer, more effective, and more precisely targeted treatments for the millions of individuals suffering from chronic pain worldwide.”

https://www.nature.com/articles/s43856-025-00996-3

The Role of the Endocannabinoid System in the Mechanism of Action of Nonopioid Analgesics

Posted on by
pubmed logo

“The endocannabinoid system (eCBS) plays a crucial role in pain modulation through its components, including endocannabinoids, cannabinoid receptors (CB1 and CB2), and metabolic enzymes.

Recent research highlights the interaction between the eCBS and non-opioid analgesics, including nonsteroidal anti-inflammatory drugs (NSAIDs), acetaminophen, and pyrazolones. These agents may enhance endogenous endocannabinoid levels or influence eCBS signaling pathways, providing a multifaceted approach to pain relief.

This review examines the pharmacological mechanisms underlying these interactions, focusing on the potential of non-opioid eCBS interactions, detailing synergistic effects that could improve analgesic efficacy while minimizing side effects. Additionally, we explore the therapeutic implications of co-administering non-opioid analgesics with eCBS modulators to create more effective pain management strategies.

The combined modulation of non-opioid pathways and the eCBS represents a promising treatment for acute and chronic pain, warranting further clinical investigation and translational research in this evolving field.”

https://pubmed.ncbi.nlm.nih.gov/40659176/

“Emerging Therapeutic Strategies: The integration of non-opioid medications with eCBS modulators represents a novel approach in pain management strategies, aiming to minimize opioid use while maximizing therapeutic efficacy and safety profiles during chronic pain management.”

https://www.sciencedirect.com/science/article/abs/pii/S0014299925007009?via%3Dihub